In the federal IT workforce, the number of employees age 60 or older is more than quadruple the number of specialists under the age of 30, according to a Nextgov analysis.

The government employed roughly 1.8 IT workers age 60 or older for every IT employee under 30 years old in 2007, but that ratio more than doubled over the next 10 years, widening to 4.5 IT specialists age 60-plus per employee under 30 by 2017.

The analysis used data gathered from OPM’s FedScope portal on government workers employed under series 2210 positions, designated as “Information Technology Management.” Employees were broken down into 10 age groups; the youngest being 20 to 24 years old and the oldest ages 65 and older. To understand how the age gap has changed over the years, Nextgov calculated the annual ratio of IT employees age 60 and older to those in their 20s from 2007 to 2017.

The IT workforce grew significantly during that period, expanding from about 65,200 employees in 2007 to more than 84,400 by 2017. As many specialists approach retirement, most agencies are struggling to find fresh faces to take their place.

In recent years, the ratio of feds ages 60 and older to those under 30 showed annual growth of about 0.39, beginning at 1.92-to-1 in 2010 and eventually reaching 4.53-to-1 in September 2017.

Nextgov found the trend has been driven almost exclusively by an increase in older employees rather than a decrease in younger workers.

The government has employed between 2,500 and 4,000 IT specialists under 30 every year for the last decade, but since 2007, the number of retirement-age federal tech workers more than doubled from about 5,300 to more than 11,500 in 2017.

The issue of aging employees isn’t unique to IT—the median age of the federal workforce has climbed from 30 to 42 since the late 1980s. But while workers have gotten older all across government, the age gap in IT has been especially stark.

The ratio of feds ages 60 and older to those under 30 nearly doubled from 1.08-to-1 in 2007 to 2.03-to-1 in 2017, but even so, the widening disparity pales in comparison to the growing age gap in IT positions.